In the conventional vehicle seat heater as shown in FIG. 1 and FIG. 2, seat heater main body 4 is constructed by wiring cord-shaped warming heater 2 in zig zag shape on substrate body 1 consisting of a polyester non-woven fabric, or the like, and by heat-press-bonding (or a similar process) surface cloth 3, which has a thermal fusing adhesive, on both sides of the substrate body 1. On one part of the seat heater main body 4, a thermostat 5 is mounted to directly sense the heat of the seat heater warming part 4'. Lead wires 6 are connected to the thermostat 5 and the above-mentioned warming heater 2, and connection plug 7 for connecting the vehicle seat heater to a power source (not shown) of an automobile. The above-mentioned seat heater main body 4 is, as shown in FIG. 3, mounted on a seat part 8a and a seat back part 8b of a vehicle seat 8. The above-mentioned mounting of the seat heater main body is made, as shown in FIG. 4, by inserting and disposing heater main body 4 between a pad 9 formed of foamed urethane and a cushion material 10 made of foamed urethane. Incidentally, numeral 11 is the surface leather of the vehicle seat.
In the above-mentioned configuration, however, since thermostat 5, which controls the flow of electricity to the heater 2 by detecting the temperature of the warming heater 2, is mounted on one part of the seat heater main body 4, and the seat heater main body 4 is mounted in the vehicle seat 8, the thermostat 5 causes a bump to be formed in the seat surface, and as a result, the user feels uncomfortable when sitting on the vehicle seat.
A solution has been proposed which mounts the thermostat in a part of the seat not touching the user, namely at the part where the seat cushion part 8a and the seat back part 8b are superposed, or mounting it between the legs of the user. However, these solutions require thermostat temperature settings unique to each vehicle seat shape, since heating characteristics vary depending on respective vehicle seat configurations due to the shape of the vehicle seat 8 and the shape and volume of the cushion material 10. Therefore, mounting the thermostat in such locations has been troublesome.